The present invention is generally related to an electrical interface for a sensor element, and, more particularly, to an integrated circuit (IC) based electrical interface between the sensor element and a data acquisition system (DAS), as may be used as a modular tileable element in a large area detector for in a computed tomography (CT) system.
Radiographic imaging systems, such as X-ray and computed tomography (CT) have been employed for observing, in real time, interior aspects of an object. Typically, the imaging systems include an X-ray source that is configured to emit X-rays toward an object of interest, such as a patient or a piece of luggage. A detecting device, such as an array of radiation detectors, is positioned on the other side of the object and is configured to detect the X-rays transmitted through the object.
One known detector used in a computed tomography (CT) system includes an energy discriminating, direct conversion detector. When subjected to x-ray energy, a sensor element in the direct conversion detector converts this x-ray to energy to produce an analog electrical signal corresponding to an incident photon flux.
A data acquisition system (DAS) may acquire the analog signals from the direct conversion detector and convert these signals to digital signals for subsequent processing. Interface packages traditionally utilized between the detector and the DAS have not enabled achieving optimal signal integrity for the analog signals. One factor in this non-optimal signal quality is the interconnect paths between the sensor element and the DAS. Current detector modules make interconnections from the sensor readout surface to the DAS with an interconnect structure involving long length metal traces on flexible or rigid circuit board. As the density of sensor elements increases, the routing of interconnects between the DAS and sensor becomes more difficult. More layers of packaging are required to route the interconnects, thus causing increased capacitance and decreased reliability.
Accordingly, it is desirable to provide a system of interconnects that provides short, low capacitance interconnection of a sensor element to the DAS. Furthermore, it is desirable that the sensor and signal processing electronics are packaged in a tileable unit with two, three, or four sides that butt to form a sensor array that has relatively small gaps between the units.